This invention relates to electrical connectors. More particularly it relates to modular jacks commonly known as FCC connectors.
The Federal Communications Commission has adopted certain architectural standards with respect to electrical connectors utilized in the telephone industry so as to provide intermateability. These connectors are commonly referred to as FCC type modular plugs and jacks. The plug is commonly terminated to a plurality of wires which may be connected to a telephone handset or other communicating device. The corresponding jack is commonly mounted to a panel such as a wall plate and terminated to a plurality of wires which lead to a telecommunication network.
A typical plug is described in U.S. Pat. No. 4,431,246 and a typical jack is described in U.S. Pat. No. 4,648,678. The outer dimensions of the plug, along with the entry dimensions of the jack are such that plugs may be snap fitted into corresponding jacks. Each plug includes a plurality of spaced apart contacts, usually four, six or eight fixed contacts, located on spaced apart centers, again the spacing being controlled by FCC specifications. The jack includes a plurality of spring contacts which again are spaced apart pursuant to FCC specifications so as to align with and make proper electrical contact with the corresponding fixed contacts of the plug.
Because the contacts of the jack are spring contacts and thus movable, problems sometimes arise with the jacks because of overdeflection of the spring contacts. Once a spring contact is overdeflected, it more than likely will not return to its original position within the jack resulting in failure of the connection. The overdeflection can occur under normal use but more than likely will occur because of abuse or because of the common practice of one inserting a six contact plug into an eight contact jack. Because the six contact plug normally has plastic shoulders which extend above the normal level of the contacts, the outer two contacts of the jack will become overdeflected when the six contact plug is placed in the eight contact jack. Poor mechanical design of the jack contacts or the selection of inappropriate contact materials or a combination of both will exacerbate the problem. Because of this problem of overdeflection, often connector manufacturers have resorted to the use of expensive materials in the manufacture of spring contacts such as, for example, beryllium copper alloys. Beryllium copper is known to have better spring properties than the less expensive phosphorous/bronze alloys. Depending on the current market for the metals, often the beryllium copper alloys are five times more expensive than phosphorous/bronze alloys. Cost becomes an additional problem because of the large amount of waste of materials which occurs during the manufacture of the contacts. Furthermore, the contact manufacturer is unable to recover much from recycling the waste. It is therefore desirable to provide a jack having spring contacts made of less expensive materials and which are not prone to damage from overdeflection.